Results of the use of Kahoot! gamification tool in a course of Chemistry

[EN] The present study examines the use of Kahoot! as a gamification tool to explore mixed learning strategies. We analyze its use in two different groups of a theoretical subject of the third course of the Degree in Chemistry. An empirical-analytical methodology was used using Kahoot! in two different groups of students, with different frequencies. The academic results of these two group of students were compared between them and with those obtained in the previous course, in which Kahoot! was not employed, with the aim of measuring the evolution in the students´ knowledge. The results showed, in all cases, that the use of Kahoot! has led to a significant increase in the overall marks, and in the number of students who passed the subject. Moreover, some differences were also observed in students´ academic performance according to the group. Finally, it can be concluded that the use of a gamification tool (Kahoot!) in a university classroom had generally improved students´ learning and marks, and that this improvement is more prevalent in those students who have achieved a better Kahoot! performance.Authors gratefully acknowledge funding (Universidad de Valladolid, Área de Formación e Innovación Docente; Project Nº12). The authors wish also to thank David Rixham (White Rose English School, Valladolid, Spain) for performing the English revision.http://ocs.editorial.upv.es/index.php/HEAD/HEAD18Ares, AM.; Bernal, J.; Nozal, MJ.; Sánchez, FJ.; Bernal, J. (2018). Results of the use of Kahoot! gamification tool in a course of Chemistry. Editorial Universitat Politècnica de València. 1215-1222. https://doi.org/10.4995/HEAD18.2018.8179OCS1215122

Torque de desinserción y propiedades fisico-químicas de implantes dentales grabados con ácidos fluorhídrico y nítrico: estudio experimental en perros Beagle

Objetivo: Estudiar la composición, características superficiales y respuesta al torque de desinserción de una superficie implantaria tratada inicialmente con ácido fluorhídrico y posterior pasivado con ácidos fluorhídrico y nítrico. Diseño del estudio: En una primera fase, se seleccionaron 12 implantes en los que se estudiaron las características fisico-químicas mediante mediciones de energía dispersa de rayos X (EDS), microscopio electrónico de barrido y análisis de XPS (espectrometría de fotoelectrones). Asimismo, se colocaron 24 implantes 'doce de 8 mm y doce de 10 mm de longitud-, en seis perros beagle, en los que tras un período de reposo, se procedió a la retirada de 12 implantes a las seis semanas y los 12 restantes a las doce semanas, mediante un calibrador de torque Gauge TonichiR modelo BGT150CN-S -con un rango de registro de fuerza de 0 a 150 Ncm. Resultados: El análisis de la composición química superficial mediante EDS sólo mostró la presencia de titanio en las superficies grabadas. En el análisis mediante XPS, al igual que sucede con las superficies de otros implantes dentales, aparecieron trazas de otros elementos presentes en la superficie, fundamentalmente de carbono. La morfología de la superficie tras el doble grabado con ácido, permitió observar la rugosidad creada por el ataque ácido, con una morfología bastante homogénea. Los valores de rugosidad obtenidos fueron superiores al micrómetro. Los valores medios encontrados para el torque de desinserción, a las seis semanas, fueron de 79,7 Ncm para los implantes de 8 mm de longitud y 115 Ncm para los implantes de 10 mm. A las doce semanas, estos valores incrementaron hasta 101,2 Ncm para los implantes de 8 mm y 139,7 Ncm para los implantes de 10 mm de longitud. Conclusiones: El grabado con ácido fluorhídrico y nítrico, posee características superficiales óptimas y comparables al de otras superficies. Los valores de torque de desinserción abren la posibilidad para su aplicación en clínica humana para procedimientos de carga precoz o inmediata.Objective: To study the composition, surface characteristics and response to removal torque of an implant surface subjected to hydrofluoric acid etching and posterior passivating with hydrofluoric and nitric acid. Study design: Twelve implants were initially selected and their physico-chemical characteristics were evaluated by means of energy-dispersive X-rays (EDS), scanning electron microscopy (SEM) and photoelectron spectroscopy (XPS). In addition, 24 implants ' 12 measuring 8 mm and 12 measuring 10 mm in length ' were implanted in 6 Beagle dogs. Twelve implants were removed after a recovery period of 6 weeks, followed by removal of the remaining 12 implants after 12 Medeweeks, using a torque calibrator (Gauge Tonichi® model BGT150CN-S) with a force registry range of 0-150 Ncm. Results: EDS analysis of the surface chemical composition only revealed the presence of titanium in the etched surfaces. In the same way as with the surfaces of other dental implants, XPS analysis revealed traces of other elements present in the surface, fundamentally carbon. Following dual acid etching, the surface showed the roughness resulting from acid action, with a morphology that proved to be quite homogeneous. The roughness values obtained exceeded 1 ìm. The mean removal torque values after 6 weeks were 79.7 Ncm for the 8 mm implants and 115 Ncm for the 10 mm implants. After 12 weeks, these values increased to 101.2 Ncm and 139.7 Ncm, respectively. Conclusions: Hydrofluoric and nitric acid etching affords optimum surface characteristics comparable to those of other surfaces. The recorded removal torque values raise the possibility of human clinical application for early or immediate loading procedures

Seismic hazard in Andalucia region (Southern Spain)

The global objective of the SISMOSAN Project has been to provide a general seismic risk assessment of Andalusian region (Southern Spain) associated with the ground motions expected for a return period of 475 years. The project was financed by Civil Defence of Andalusia and its results will be applied to the definition of regional emergency plans. We present here the study and main results of the first phase of the project, aimed at evaluating seismic hazard. In contrast to most of the previous studies in the region, which were performed for peak ground accelerations (PGA) making use of Intensity-to-PGA relationships, hazard was here calculated in terms of magnitude and using published spectral ground-motion models. Moreover, we have considered distinct models for the Atlantic earthquakes, since the attenuation of those motions seem to be slower, as evidenced by the extensive macroseismic areas of the 1755, 1969 and 2007 earthquakes. A comprehensive revision of the seismic catalogue, as well as of the seismogenic models proposed for the region (including those for North Africa, which is part of the influence area) has been done. In a first step, seismic hazard was evaluated at generic rock sites covering the entire region, using a seismic catalogue homogenized to moment magnitude and considering attenuation models in terms of PGA and spectral ordinates (SA). A Probabilistic Seismic Hazard Assessment (PSHA) methodology was followed using a logic tree, in order to constrain the epistemic uncertainty, including two nodes for different options of zonification and attenuation models. In a second step, a geotechnical characterization of the whole region has been carried out, mainly inferred from geological maps and refined with on-site data, which are combined with rock acceleration estimates, in order to compose hazard maps that incorporate local soil effects

Fucoxanthin-Containing Cream Prevents Epidermal Hyperplasia and UVB-Induced Skin Erythema in Mice

Microalgae represent a source of bio-active compounds such as carotenoids with potent anti-inflammatory and antioxidant properties. We aimed to investigate the effects of fucoxanthin (FX) in both in vitro and in vivo skin models. Firstly, its anti-inflammatory activity was evaluated in LPS-stimulated THP-1 macrophages and TNF-α-stimulated HaCaT keratinocytes, and its antioxidant activity in UVB-irradiated HaCaT cells. Next, in vitro and ex vivo permeation studies were developed to determine the most suitable formulation for in vivo FX topical application. Then, we evaluated the effects of a FX-containing cream on TPA-induced epidermal hyperplasia in mice, as well as on UVB-induced acute erythema in hairless mice. Our results confirmed the in vitro reduction of TNF-α, IL-6, ROS and LDH production. Since the permeation results showed that cream was the most favourable vehicle, FX-cream was elaborated. This formulation effectively ameliorated TPA-induced hyperplasia, by reducing skin edema, epidermal thickness, MPO activity and COX-2 expression. Moreover, FX-cream reduced UVB-induced erythema through down-regulation of COX-2 and iNOS as well as up-regulation of HO-1 protein via Nrf-2 pathway. In conclusion, FX, administered in a topical formulation, could be a novel natural adjuvant for preventing exacerbations associated with skin inflammatory pathologies as well as protecting skin against UV radiation

Potentiometric study of carbon nanotube/surfactant interactions by ion-selective electrodes. Driving forces in the adsorption and dispersion processes

The interaction (adsorption process) of commercial ionic surfactants with non-functionalized and functionalized carbon nanotubes (CNTs) has been studied by potentiometric measurements based on the use of ion-selective electrodes. The goal of this work was to investigate the role of the CNTs' charge and structure in the CNT/surfactant interactions. Non-functionalized single- (SWCNT) and multi-walled carbon nanotubes (MWCNT), and amine functionalized SWCNT were used. The influence of the surfactant architecture on the CNT/surfactant interactions was also studied. Surfactants with different charge and hydrophobic tail length (sodium dodecyl sulfate (SDS), octyltrimethyl ammonium bromide (OTAB), dodecyltrimethyl ammonium bromide (DoTAB) and hexadecyltrimethyl ammonium bromide (CTAB)) were studied. According to the results, the adsorption process shows a cooperative character, with the hydrophobic interaction contribution playing a key role. This is made evident by the correlation between the free surfactant concentration (at a fixed [CNT]) and the critical micellar concentration, cmc, found for all the CNTs and surfactants investigated. The electrostatic interactions mainly determine the CNT dispersion, although hydrophobic interactions also contribute to this process.Fil: Ostos, Francisco José. Universidad de Sevilla; EspañaFil: Lebrón, José Antonio. Universidad de Sevilla; EspañaFil: Moyá, María Luisa. Universidad de Sevilla; EspañaFil: Bernal, Eva. Universidad de Sevilla; EspañaFil: Flores, Ana. Universidad de Huelva; EspañaFil: Lépori, Cristian Marcelo Oscar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; ArgentinaFil: Maestre, Ángeles. Universidad de Huelva; EspañaFil: Sánchez, Francisco. Universidad de Sevilla; EspañaFil: López Cornejo, Pilar. Universidad de Sevilla; EspañaFil: López López, Manuel Carlos. Universidad de Huelva; Españ

Removal torque and physico-chemical characteristics of dental implants etched with hydrofluoric and nitric acid : an experimental study in Beagle dogs

Objective: To study the composition, surface characteristics and response to removal torque of an implant surface subjected to hydrofluoric acid etching and posterior passivating with hydrofluoric and nitric acid. Study design: Twelve implants were initially selected and their physico-chemical characteristics were evaluated by means of energy-dispersive X-rays (EDS), scanning electron microscopy (SEM) and photoelectron spectroscopy (XPS). In addition, 24 implants ? 12 measuring 8 mm and 12 measuring 10 mm in length ? were implanted in 6 Beagle dogs. Twelve implants were removed after a recovery period of 6 weeks, followed by removal of the remaining 12 implants after 12 weeks, using a torque calibrator (Gauge Tonichi® model BGT150CN-S) with a force registry range of 0-150 Ncm. Results: EDS analysis of the surface chemical composition only revealed the presence of titanium in the etched surfaces. In the same way as with the surfaces of other dental implants, XPS analysis revealed traces of other elements present in the surface, fundamentally carbon. Following dual acid etching, the surface showed the roughness resulting from acid action, with a morphology that proved to be quite homogeneous. The roughness values obtained exceeded 1 µm. The mean removal torque values after 6 weeks were 79.7 Ncm for the 8 mm implants and 115 Ncm for the 10 mm implants. After 12 weeks, these values increased to 101.2 Ncm and 139.7 Ncm, respectively. Conclusions: Hydrofluoric and nitric acid etching affords optimum surface characteristics comparable to those of other surfaces. The recorded removal torque values raise the possibility of human clinical application for early or immediate loading procedures